Mass. Gen. Laws ch. 140 § 131K
Any firearm or large capacity weapon, both as defined in section 121, sold within the commonwealth without a safety device designed to prevent the discharge of such weapon by unauthorized users and approved by the colonel of state police including, but not limited to, mechanical locks or devices designed to recognize and authorize, or otherwise allow the firearm to be discharged only by its owner or authorized user, by solenoid use-limitation devices, key activated or combination trigger or handle locks, radio frequency tags, automated fingerprint identification systems or voice recognition, provided, that such device is commercially available, shall be defective and the sale of such a weapon shall constitute a breach of warranty under section 2-314 of chapter 106 and an unfair or deceptive trade act or practice under section 2 of chapter 93A. Any entity responsible for the manufacture, importation or sale as an inventory item or consumer good, both as defined in section 9-102 of chapter 106, of such a weapon that does not include or incorporate such a device shall be individually and jointly liable to any person who sustains personal injury or property damage resulting from the failure to include incorporate such a device. If death results from such personal injury, such entities shall be liable in an amount including, but not limited to, that provided under chapter 229. Contributory or comparative negligence shall not be valid defenses to an action brought under this section in conjunction with section 2 of chapter 93A or section 2-314 of chapter 106 or both; provided, however, that nothing herein shall prohibit such liable parties from maintaining an action for indemnification or contribution against each other or against the lawful owner or other authorized user of said weapon. Any disclaimer, limit or waiver of the liability provided under this section shall be void.
No entity responsible for the manufacture, importation or sale of such a weapon shall be liable to any person for injuries caused by the discharge of such weapon that does not include or incorporate a safety device as required under this section if such injuries were: (i) self-inflicted, either intentionally or unintentionally, unless such injuries were self-inflicted by a person less than 18 years of age; (ii) inflicted by the lawful owner or other authorized use of said weapon; (iii) inflicted by any person in the lawful exercise of self-defense; or (iv) inflicted upon a co-conspirator in the commission of a crime.
This section shall not apply to any weapon distributed to an officer of any law enforcement agency or any member of the armed forces of the United States or the organized militia of the commonwealth; provided, however, that such person is authorized to acquire, possess or carry such a weapon for the lawful performance of his official duties; and provided further, that any such weapon so distributed is distributed solely for use in connection with such duties. This section shall not apply to any firearm manufactured in or prior to the year 1899, or to any replica of such a firearm if such replica is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition.
Mass. Gen. Laws ch. 140, § 131K